Dona Croll(Doctors, Tula: The Revolt) and Georgina Campbell(One Night) also have supporting roles in the Left Bank Pictures production; Croll as Serena’s mother, Rachel, and Campbell as young Serena.

From ITV . . .

“The story follows two vulnerable teenage
girls who, in the summer of 1995, are accused of murdering their
schoolteacher. For seventeen years, the two girls go their separate
ways, Poppy having been charged with the murder. Now in 2013, they are
forced to confront each other and their dark, shared history.”